Description Usage Arguments Details Value Author(s) References See Also Examples
View source: R/pois.fe.robust.R
Compute standard errors following Wooldridge (1999) for Poisson regression with fixed effects, and a hypothesis test of the conditional mean assumption (3.1).
1 2 3 | pois.fe.robust(outcome, xvars, group.name, data,
qcmle.coefs = NULL, allow.set.key = FALSE,
index.name = NULL)
|
outcome |
character string of the name of the dependent variable. |
xvars |
vector of character strings of the names of the independent variables. |
group.name |
character string of the name of the grouping variable. |
data |
data.table which contains the variables named in other arguments. See details for variable type requirements. |
qcmle.coefs |
an optional numeric vector of coefficients in the same order as |
allow.set.key |
logical. When |
index.name |
DEPRECATED (leave as NULL). |
data
must be a data.table
containing the following:
a column named by outcome
, non-negative integer
columns named according to each string in xvars
, numeric type
a column named by group.name
, factor type
a column named by index.name
, integer sequence increasing by one
each observation with no gaps within groups
No observation in data
may contain a missing value.
Setting allow.set.key
to TRUE
is recommended to reduce
memory usage; however, it will allow data
to be modified
(sorted in-place).
pois.fe.robust
also returns the p-value of the hypothesis test of the
conditional mean assumption (3.1) as described in Wooldridge (1999) section 3.3.
A list containing
coefficients
, a numeric vector of coefficients.
se.robust
, a numeric vector of standard errors.
p.value
, the p-value of a hypothesis test of the
conditional mean assumption (3.1).
Evan Wright
Wooldridge, Jeffrey M. (1999): "Distribution-free estimation of some nonlinear panel data models," Journal of Econometrics, 90, 77-97.
1 2 3 4 5 6 7 8 9 | # ex.dt.good satisfies the conditional mean assumption
data("ex.dt.good")
pois.fe.robust(outcome = "y", xvars = c("x1", "x2"), group.name = "id",
index.name = "day", data = ex.dt.good)
# ex.dt.bad violates the conditional mean assumption
data("ex.dt.bad")
pois.fe.robust(outcome = "y", xvars = c("x1", "x2"), group.name = "id",
index.name = "day", data = ex.dt.bad)
|
$coefficients
x1 x2
0.9899730 0.9917526
$se.robust
x1 x2
0.03112512 0.02481941
$p.value
[1] 0.6996001
Warning messages:
1: In pois.fe.robust(outcome = "y", xvars = c("x1", "x2"), group.name = "id", :
index.name is deprecated. It is not necessary.
2: In pois.fe.robust(outcome = "y", xvars = c("x1", "x2"), group.name = "id", :
allow.set.key is FALSE. TRUE is recommended to avoid copying the data; however, TRUE will sort the data in-place by group.name.
$coefficients
x1 x2
0.4800735 2.9866911
$se.robust
x1 x2
0.2864666 1.2743953
$p.value
[1] 0.02213269
Warning messages:
1: In pois.fe.robust(outcome = "y", xvars = c("x1", "x2"), group.name = "id", :
index.name is deprecated. It is not necessary.
2: In pois.fe.robust(outcome = "y", xvars = c("x1", "x2"), group.name = "id", :
allow.set.key is FALSE. TRUE is recommended to avoid copying the data; however, TRUE will sort the data in-place by group.name.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.